While Patrick’s writings constitute some of the earliest literary evidence from an actual member of the British church, there is written testimony going back to the second century regarding the presence of Christianity in the British Isles. In the 190s the North African author Tertullian (fl. 190-220), for instance, states in his Against the Jews that Christianity had spread so far it had reached Britain and had gone beyond the Antonine Wall. In answer to his question, “In whom else have all the nations believed, than in the Christ who has already come?” he states that even “places in Britain…, though inaccessible to the Romans, have yielded to Christ.”
— Michael A. G. Haykin, Patrick of Ireland: His Life and Impact, KL 252 (emphasis added).